2002 Fiscal Year Final Research Report Summary
Effect on optic nerve of silicone oil tamponade in rabbits
| Project/Area Number |
13671842
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Ophthalmology
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| Research Institution | NAGASAKI UNIVERSITY |
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Principal Investigator |
GONG Huaqing Dept. of Ophthalmology and Visual Sciences, Lecturer, 医学部附属病院, 講師 (70304938)
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| Co-Investigator(Kenkyū-buntansha) |
AMEMIYA Tsugio Dept. of Ophthalmology and Visual Sciences, Professor, 大学院・医歯薬学総合研究科, 教授 (60026862)
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| Project Period (FY) |
2001 – 2002
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| Keywords | Silicone oil Tamponade / energy dispersive Xray analysis / gas mediated vitreous compression |
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| Research Abstract |
Purpose : Side effects after intravitreal use of silicone oil (SO) are not yet well defined and elucidated. The object of this study is to examine the influence and toxicity of silicone oil on the optic nerve after vitrectomy with SO tamponade. Methods : We injected medical grade SO and emulsified SO into rabbit eyes after gas-mediated vitreous compression and examined them by light microscopy (LM), transmission electron microscopy (TEM), and energy dispersive X-ray analysis (EDXA) (point analysis and area analysis) 6 months after injection. We compared the findings in the non-treated eyes and eyes with only gas-mediated vitreous compression with those in SO-injected eyes. Results : Vacuole-like structures were seen in the optic nerve posterior to the lamina cribrosa. In group G the myelin structures were shown by TEM to be destroyed and replaced by glial tissue, while in groups M6 and E6, severe destruction of the myelin sheath (myelinolysis) was observed Silicone was identified at the electron dense edges of the vacuoles by EDXA point analysis, but not in the vacuoles without electron dense deposits. Dots of Si K alpha were not seen in the control groups, and dense dots were observed in SO injected groups, by EDXA area analysis. Conclusions : Some of the vacuoles might be artifacts caused by insufficient fixation or the operative procedure, but TEM showed almost no artifacts in the contrl optic nerve. Thus, most vacuoles may be SO storage sites. SO uptake into the optic nerve might play a role in the pathogenesis of optic nerve atrophy after SO injection.
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